I'm an iPhone developer, how can I integrate WhatsApp into my app?

WhatsApp provides two ways for your iPhone app to interact with WhatsApp:

Through a custom URL scheme

Through the iOS Document Interaction API

Custom URL Scheme

If your application would like to open a WhatsApp Chat with a specific contact, you can use our custom URL scheme to do so. Opening whatsapp:// followed by one of the following parameters, will open WhatsApp and perform a custom action.

URL

Parameters

Opens

app

—

The WhatsApp Messenger application

send

—

New chat composer

abid

Address book ID of contact to start a chat with.
If contact with this ID has only one whatsapp-able phone number, application will open a conversation with that contact.
If contact with this ID has more than one whatsapp-able phone numbers, application will present a menu with all phone numbers available for chat.
If contact has no whatsapp-able phone numbers, or contact with this ID does not exist, or this parameter is missing, application will present contact picker listing all contacts available for chat via WhatsApp.

text

If present, this text will be pre-filled into message text input field on a conversation screen.

Document Interaction

If your application creates photos, videos or audio notes and you’d like your users to share these media using WhatsApp, you can use the Document Interaction API to send your media to your WhatsApp contacts and groups.

WhatsApp Messenger can handle various types of media:

images of any type that conforms to public.image (for example, PNG and JPEG)

videos of any type that conforms to public.movie (for example, MPEG-4 video)

audio files (only MPEG-3, MPEG-4, AIFF, AIFF-C and Core Audio)

Alternatively, if you want to show only WhatsApp in the application list (instead of WhatsApp plus any other public/*-conforming apps) you can specify a file of one of aforementioned types saved with the extension that is exclusive to WhatsApp:

images - «.wai» which is of type net.whatsapp.image

videos - «.wam» which is of type net.whatsapp.movie

audio files - «.waa» which is of type net.whatsapp.audio

When triggered, WhatsApp will immediately present the user with the contact/group picker screen. The media will be automatically sent to a selected contact/group.

About WhatsApp

WhatsApp Messenger is a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for iPhone, BlackBerry, Windows Phone, Android and Nokia.